Track-edge noise versus erasure state

Track-edge noise was evaluated by means of spectrum analyzer measurements performed on isolated tracks, one recorded at 16 kfci and the other 40 kfci, on CoCrPt, CoNiPt, and CoCrTa media. The track-edge media noise correlated with intergranular exchange coupling and the initial erasure state of the media. This study of track-edge effects has confirmed the nature and existence of side-erase bands, located on either side of a recorded track for the three different thin-film media. Track-edge media noise was more noticeable for the 16 kfci tracks recorded on both previously AC- and DC-erased media. The track edges for the 40 kfci track recorded on previously DC-erased media proved to be regions of high noise which extended beyond the radial extent of the written track